I agree that the gas pedal is "mushy" in Eco Mode and not too bad in Sport mode. At a stop light, if I have no traffic behind me and I have time on my hands, I leave it in Eco Mode and take off smoothly. If there is traffic behind, I move it over to Sport mode and get the added boost of higher shift points, then switch it back eco mode when up to speed. I mostly have no traffic and time on my hands and is probably the reason why I am averaging around 60 MPG.
I also find that in Eco mode the car loses speed easily on any up hill while trying to add some gas to maintain speed, but it seems like you have to give it a lot of gas relative to my brain/foot ratio from my former cars. What I find I have to do is at the bottom of the hill I move the shifter to sport mode and this helps greatly. After the crest, I just move it back to Eco mode. It is a car that I find I have to work at to drive it and keep up with traffic, kind of like a low powered standard shift car.
Also, here are my observations of using Sport mode: YMMV
1. When moving the shifter to Sport mode, you always get the "D" switching to a "5" displayed, no matter how fast you are going. I guess the "5" is close to looking like an "S".
2. If left alone, the car will have higher shift points, won't as easily go into "EV" only mode and the "5" will always be displayed.
3. If you manually up or down shift, the car will then display the correct gear that the transmission is in.
4. Not totally sure on this one but, if you are at a stop light and switch to Sport mode and then down shift, the "1" will be displayed. When you take off, the car will stay in first gear until you manually up shift it to "2". I tried to let the car shift itself but, the engine was revving so high I didn't want to let it go any higher before I manually up shifted. Not sure if this is true for all the gears.
Hope this helps you.